Conventionally, to deal with downsizing of a coil, what is called alpha winding (or, “outer-outer winding” in other words) such that a wire rod is closely wound not to form an unnecessary gap between winding layers, and a winding starting end and a winding terminating end of the wire rod are wired at an identical winding layer is heavily used. As this alpha winding coil, a two-row spiral coil has been known. The two-row spiral coil includes first and second coils which is made by winding the wire rod in a spiral, and an inside crossover wire that couples inner peripheral end portions of these first and second coils one another.
As a manufacturing device of the two-row spiral coil, JPH10-154626A proposes a device that includes first and second wheels, a winding wire supply portion, and a wire storing portion. The first and second wheels are opposed at an interval of a clearance by two wire rods to mutually rotate in opposite directions around a winding core. The winding wire supply portion delivers the wire rod toward a guide groove or a hole of the first wheel. The wire storing portion stores the wire rod in a winding state and delivers this wire rod toward a guide groove or a hole of the second wheel.
At this manufacturing device, the winding starts at any position of the wire rods with respect to an outer periphery of the winding core, the first and second wheels are mutually rotated in the opposite directions. In view of this, the wire rods extending to both sides from the winding starting position are simultaneously wound around the winding core mutually in the opposite directions to form winding wire portions that are two-layered in an axial direction of the winding core, at the outer periphery of the winding core. Then, leading the wire rods from outer peripheries of the respective winding wire portions can relatively easily manufacture the two-row spiral coil where the winding starting ends and the winding terminating ends of the wire rods are extracted from the identical winding layer at the outermost periphery.